Just because someone chooses to work at a TC or in any other place that you wouldnt
necessarily choose to work in doesn't automatically mean they are a lesser teacher or
indeed that they don't derive satisfaction from what they are doing. You can't possibly
be sure of those kind of things.

The teachers you mentioned I guess will have spent several years hard work studying in a Teacher Training College or at University to be teachers in the State Sector and yes they choose those places where they find motivation and job satisfaction.

Whereas Celta/TEFL/TESOL takes four weeks in a Training Centre with a few hours practicum - as you say it doesn't necessarily mean that anyone is a lesser teacher - it's where they work that is the lesser.

However in my opinion for what it's worth, I think that someone who has completed several years training will probably look higher than a Training Centre Corporation for employment.